Search results for " Hydrodynamic"

Boulder dynamics in the Favignana Island coastal zone (Egadi Archipelago, Central Mediterranean)

2016

Boulders disjoined from platform edges or accumulated in the nearshore are frequently transported and deposited in the backshore as a consequence of tsunamis and high-magnitude storm waves. We investigate this process in the Favignana Island (Egadi Archipelago) coastal zone by integrating geological and morphological data with numerical hydrodynamic analysis and radiocarbon dating. Boulders and sockets are detected in proximity to the shorelines of Punta Faraglione and Punta Fanfalo, which are located in the NW and SE sectors of the Favignana Island, respectively. They are scattered on the rocky platform as isolated blocks or in small groups that, together, form a discontinuous berm. The la…

Some Numerical Remarks on a Meshless Approximation Method

2016

In this paper we consider sources of enhancement for the Smoothed Particle Hydrodynamics method in approximating a function and its derivatives. It is well known that the standard formulation is usually poor when scattered data distribution is considered or when the approximation near the boundary occurs. In this paper studies on the accuracy are provided and assessed with gridded and scattered data distribution in the problem domain. The improvements of the method are addressed and supporting numerical experiments are included.

A Meshless Method for Image Reconstruction

2009

ADVANCED MESHLESS NUMERICAL METHODS AND APPLICATIONS

Consistency Restoring in SPH for Trigonometric Functions Approximation

2009

Shock oscillation model for quasi-periodic oscillations in stellar mass and supermassive black holes

2007

We numerically examine centrifugally supported shock waves in 2D rotating accretion flows around a stellar-mass (10M_sun) and a supermassive (10^6M_sun) black holes over a wide range of input accretion rates of 10^7 >\dot M/\dot M_E>10^{-4}. The resultant 2D-shocks are unstable with time and the luminosities show quasi-periodic oscillations (QPOs) with modulations of a factor of 2-3 andwith periods of a tenth seconds to several hours, depending on the black hole masses. The shock oscillation model may explain the intermediate frequency QPOs with 1-10 Hz observed in the stellar-mass black hole candidates and also suggest the existence of QPOs with the period of hours in AGNs. When the accret…

MODELING SNR CASSIOPEIA A from the SUPERNOVA EXPLOSION to ITS CURRENT AGE: The ROLE of POST-EXPLOSION ANISOTROPIES of EJECTA

2016

The remnants of core-collapse supernovae (SNe) have complex morphologies that may reflect asymmetries and structures developed during the progenitor SN explosion. Here we investigate how the morphology of the SNR Cassiopeia A (Cas A) reflects the characteristics of the progenitor SN with the aim to derive the energies and masses of the post-explosion anisotropies responsible for the observed spatial distribution of Fe and Si/S. We model the evolution of Cas A from the immediate aftermath of the progenitor SN to the three-dimensional interaction of the remnant with the surrounding medium. The post-explosion structure of the ejecta is described by small-scale clumping of material and larger-s…

A distributed-memory MPI parallelization scheme for multi-domain incompressible SPH

2022

A parallel scheme for a multi-domain truly incompressible smoothed particle hydrodynamics (SPH) approach is presented. The proposed method is developed for distributed-memory architectures through the Message Passing Interface (MPI) paradigm as communication between partitions. The proposal aims to overcome one of the main drawbacks of the SPH method, which is the high computational cost with respect to mesh-based methods, by coupling a multi-resolution approach with parallel computing techniques. The multi-domain approach aims to employ different resolutions by subdividing the computational domain into non-overlapping blocks separated by block interfaces. The particles belonging to differe…

Inner Edge Drag by an Asynchronous Primary and Accretion Disc Structure In Close Binaries

1996

In this work a 3-D ‘Smoothed Particle Hydrodynamics’ ([1]; [4]; [5]) accretion disc is simulated where particles at its inner edge are dragged by a fast spinning compact central star, as in the case of the intermediate polars. The angular velocity of the central star is twice the orbital angular velocity w 0. This drag can be attributed mainly to viscous interaction in the dense compact star atmosphere, although magnetic coupling may also play a role.

First Experiences on an Accurate SPH Method on GPUs

2017

It is well known that the standard formulation of the Smoothed Particle Hydrodynamics is usually poor when scattered data distribution is considered or when the approximation near the boundary occurs. Moreover, the method is computational demanding when a high number of data sites and evaluation points are employed. In this paper an enhanced version of the method is proposed improving the accuracy and the efficiency by using a HPC environment. Our implementation exploits the processing power of GPUs for the basic computational kernel resolution. The performance gain demonstrates the method to be accurate and suitable to deal with large sets of data.